arXiv subjects

Andrew Neitzke

Publications and source records attributed to Andrew Neitzke.

59 records · Page 4Linked to original sources

arXiv2003

Greybody factors at large imaginary frequencies

Extending a computation which appeared recently in hep-th/0301173, we compute the transmission and reflection coefficients for massless uncharged scalars and gravitational waves scattered by d>=4 Schwarzschild or d=4 Reissner-Nordstrom black holes, in the limit of large imaginary frequencies. The transmission coefficient has an interpretation as the "greybody factor" which determines the spectrum of Hawking radiation. The result has an interesting structure and we speculate that it may admit a simple dual description; curiously, for Reissner-Nordstrom the result suggests that this dual description should involve both the inner and outer horizons. We also discuss some numerical evidence in favor of the formulas of hep-th/0301173.

hep-th↗

arXiv2002

Large N Strong Coupling Dynamics in Non-Supersymmetric Orbifold Field Theories

We give a recipe relating holomorphic quantities in supersymmetric field theory to their descendants in non-supersymmetric Z_2 orbifold field theories. This recipe, consistent with a recent proposal of Strassler, gives exact results for bifermion condensates, domain wall tensions and gauge coupling constants in the planar limit of the orbifold theories.

hep-th↗

arXiv2001

A Mysterious Duality

We establish a correspondence between toroidal compactifications of M-theory and del Pezzo surfaces. M-theory on T^k corresponds to P^2 blown up at k generic points; Type IIB corresponds to P^1\times P^1. The moduli of compactifications of M-theory on rectangular tori are mapped to Kahler moduli of del Pezzo surfaces.The U-duality group of M-theory corresponds to a group of classical symmetries of the del Pezzo represented by global diffeomorphisms. The half-BPS brane charges of M-theory correspond to spheres in the del Pezzo, and their tension to the exponentiated volume of the corresponding spheres. The electric/magnetic pairing of branes is determined by the condition that the union of the corresponding spheres represent the anticanonical class of the del Pezzo. The condition that a pair of half-BPS states form a bound state is mapped to a condition on the intersection of the corresponding spheres. We present some speculations about the meaning of this duality.

hep-th↗

arXiv2000

Rationality, quasirationality and finite W-algebras

Some of the consequences that follow from the C_2 condition of Zhu are analysed. In particular it is shown that every conformal field theory satisfying the C_2 condition has only finitely many n-point functions, and this result is used to prove a version of a conjecture of Nahm, namely that every representation of such a conformal field theory is quasirational. We also show that every such vertex operator algebra is a finite W-algebra, and we give a direct proof of the convergence of its characters as well as the finiteness of the fusion rules.

hep-th↗

arXiv2000

Zhu's Theorem and an algebraic characterization of conformal blocks

Working in the axiomatic framework recently proposed by Gaberdiel and Goddard, we prove a generalized version of Zhu's Theorem; for any chiral bosonic conformal field theory on the sphere, our result characterizes the chiral blocks in terms of a certain quotient of the Fock space. We also establish, under a finiteness hypothesis closely related to rationality of the theory, that the relevant Knizhnik-Zamolodchikov-type equation admits solutions.

hep-th↗